1 /* $OpenBSD: id.c,v 1.19 2009/10/27 23:59:39 deraadt Exp $ */ 2 3 /*- 4 * Copyright (c) 1991, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 */ 31 32 #include <sys/param.h> 33 34 #include <errno.h> 35 #include <grp.h> 36 #include <pwd.h> 37 #include <stdio.h> 38 #include <stdlib.h> 39 #include <string.h> 40 #include <unistd.h> 41 #include <err.h> 42 43 void current(void); 44 void pretty(struct passwd *); 45 void group(struct passwd *, int); 46 void usage(void); 47 void user(struct passwd *); 48 struct passwd * 49 who(char *); 50 51 int 52 main(int argc, char *argv[]) 53 { 54 struct group *gr; 55 struct passwd *pw; 56 int Gflag, ch, gflag, nflag, pflag, rflag, uflag; 57 uid_t uid; 58 gid_t gid; 59 60 Gflag = gflag = nflag = pflag = rflag = uflag = 0; 61 while ((ch = getopt(argc, argv, "Ggnpru")) != -1) 62 switch(ch) { 63 case 'G': 64 Gflag = 1; 65 break; 66 case 'g': 67 gflag = 1; 68 break; 69 case 'n': 70 nflag = 1; 71 break; 72 case 'p': 73 pflag = 1; 74 break; 75 case 'r': 76 rflag = 1; 77 break; 78 case 'u': 79 uflag = 1; 80 break; 81 case '?': 82 default: 83 usage(); 84 } 85 argc -= optind; 86 argv += optind; 87 88 switch(Gflag + gflag + pflag + uflag) { 89 case 1: 90 break; 91 case 0: 92 if (!nflag && !rflag) 93 break; 94 /* FALLTHROUGH */ 95 default: 96 usage(); 97 } 98 99 pw = *argv ? who(*argv) : NULL; 100 101 if (gflag) { 102 gid = pw ? pw->pw_gid : rflag ? getgid() : getegid(); 103 if (nflag && (gr = getgrgid(gid))) 104 (void)printf("%s\n", gr->gr_name); 105 else 106 (void)printf("%u\n", gid); 107 exit(0); 108 } 109 110 if (uflag) { 111 uid = pw ? pw->pw_uid : rflag ? getuid() : geteuid(); 112 if (nflag && (pw = getpwuid(uid))) 113 (void)printf("%s\n", pw->pw_name); 114 else 115 (void)printf("%u\n", uid); 116 exit(0); 117 } 118 119 if (Gflag) { 120 group(pw, nflag); 121 exit(0); 122 } 123 124 if (pflag) { 125 pretty(pw); 126 exit(0); 127 } 128 129 if (pw) 130 user(pw); 131 else 132 current(); 133 exit(0); 134 } 135 136 void 137 pretty(struct passwd *pw) 138 { 139 struct group *gr; 140 uid_t eid, rid; 141 char *login; 142 143 if (pw) { 144 (void)printf("uid\t%s\n", pw->pw_name); 145 (void)printf("groups\t"); 146 group(pw, 1); 147 } else { 148 if ((login = getlogin()) == NULL) 149 err(1, "getlogin"); 150 151 pw = getpwuid(rid = getuid()); 152 if (pw == NULL || strcmp(login, pw->pw_name)) 153 (void)printf("login\t%s\n", login); 154 if (pw) 155 (void)printf("uid\t%s\n", pw->pw_name); 156 else 157 (void)printf("uid\t%u\n", rid); 158 159 if ((eid = geteuid()) != rid) { 160 if ((pw = getpwuid(eid))) 161 (void)printf("euid\t%s\n", pw->pw_name); 162 else 163 (void)printf("euid\t%u\n", eid); 164 } 165 if ((rid = getgid()) != (eid = getegid())) { 166 if ((gr = getgrgid(rid))) 167 (void)printf("rgid\t%s\n", gr->gr_name); 168 else 169 (void)printf("rgid\t%u\n", rid); 170 } 171 (void)printf("groups\t"); 172 group(NULL, 1); 173 } 174 } 175 176 void 177 current(void) 178 { 179 struct group *gr; 180 struct passwd *pw; 181 int cnt, ngroups; 182 uid_t uid, euid; 183 gid_t groups[NGROUPS], gid, egid, lastgid; 184 char *fmt; 185 186 uid = getuid(); 187 (void)printf("uid=%u", uid); 188 if ((pw = getpwuid(uid))) 189 (void)printf("(%s)", pw->pw_name); 190 if ((euid = geteuid()) != uid) { 191 (void)printf(" euid=%u", euid); 192 if ((pw = getpwuid(euid))) 193 (void)printf("(%s)", pw->pw_name); 194 } 195 gid = getgid(); 196 (void)printf(" gid=%u", gid); 197 if ((gr = getgrgid(gid))) 198 (void)printf("(%s)", gr->gr_name); 199 if ((egid = getegid()) != gid) { 200 (void)printf(" egid=%u", egid); 201 if ((gr = getgrgid(egid))) 202 (void)printf("(%s)", gr->gr_name); 203 } 204 if ((ngroups = getgroups(NGROUPS, groups))) { 205 for (fmt = " groups=%u", lastgid = (gid_t)-1, cnt = 0; 206 cnt < ngroups; fmt = ", %u", lastgid = gid) { 207 gid = groups[cnt++]; 208 if (lastgid == gid) 209 continue; 210 (void)printf(fmt, gid); 211 if ((gr = getgrgid(gid))) 212 (void)printf("(%s)", gr->gr_name); 213 } 214 } 215 (void)printf("\n"); 216 } 217 218 void 219 user(struct passwd *pw) 220 { 221 gid_t gid, groups[NGROUPS + 1]; 222 int cnt, ngroups; 223 uid_t uid; 224 struct group *gr; 225 char *fmt; 226 227 uid = pw->pw_uid; 228 (void)printf("uid=%u(%s)", uid, pw->pw_name); 229 (void)printf(" gid=%u", pw->pw_gid); 230 if ((gr = getgrgid(pw->pw_gid))) 231 (void)printf("(%s)", gr->gr_name); 232 ngroups = NGROUPS + 1; 233 (void) getgrouplist(pw->pw_name, pw->pw_gid, groups, &ngroups); 234 fmt = " groups=%u"; 235 for (cnt = 0; cnt < ngroups;) { 236 gid = groups[cnt]; 237 (void)printf(fmt, gid); 238 fmt = ", %u"; 239 if ((gr = getgrgid(gid))) 240 (void)printf("(%s)", gr->gr_name); 241 /* Skip same gid entries. */ 242 while (++cnt < ngroups && gid == groups[cnt]); 243 } 244 (void)printf("\n"); 245 } 246 247 void 248 group(struct passwd *pw, int nflag) 249 { 250 int cnt, ngroups; 251 gid_t gid, groups[NGROUPS + 1]; 252 struct group *gr; 253 char *fmt; 254 255 if (pw) { 256 ngroups = NGROUPS + 1; 257 (void) getgrouplist(pw->pw_name, pw->pw_gid, groups, &ngroups); 258 } else { 259 groups[0] = getgid(); 260 ngroups = getgroups(NGROUPS, groups + 1) + 1; 261 } 262 fmt = nflag ? "%s" : "%u"; 263 for (cnt = 0; cnt < ngroups;) { 264 gid = groups[cnt]; 265 if (nflag) { 266 if ((gr = getgrgid(gid))) 267 (void)printf(fmt, gr->gr_name); 268 else 269 (void)printf(*fmt == ' ' ? " %u" : "%u", 270 gid); 271 fmt = " %s"; 272 } else { 273 (void)printf(fmt, gid); 274 fmt = " %u"; 275 } 276 /* Skip same gid entries. */ 277 while (++cnt < ngroups && gid == groups[cnt]); 278 } 279 (void)printf("\n"); 280 } 281 282 struct passwd * 283 who(char *u) 284 { 285 struct passwd *pw; 286 uid_t uid; 287 const char *errstr; 288 289 /* 290 * Translate user argument into a pw pointer. First, try to 291 * get it as specified. If that fails, try it as a number. 292 */ 293 if ((pw = getpwnam(u))) 294 return(pw); 295 uid = strtonum(u, 0, UID_MAX, &errstr); 296 if (!errstr && (pw = getpwuid(uid))) 297 return(pw); 298 errx(1, "%s: No such user", u); 299 /* NOTREACHED */ 300 } 301 302 void 303 usage(void) 304 { 305 (void)fprintf(stderr, "usage: id [user]\n" 306 " id -G [-n] [user]\n" 307 " id -g [-nr] [user]\n" 308 " id -p [user]\n" 309 " id -u [-nr] [user]\n"); 310 exit(1); 311 } 312